1. Field of the Invention
The present invention relates to a dye-containing photosensitive composition suitable for forming a colored image of a color filter that is used in liquid crystal display devices and solid-state image pickup devices (CCD and CMOS), to a color filter using the same, and to a production method thereof.
2. Description of the Related Art
A dying method, a printing method, an electrodeposition method and a pigment dispersion method are known as methods of preparing a color filter that is used for liquid crystal display devices and solid-state image pickup devices.
Among these, the pigment dispersion method is a method where a color filter is prepared by photolithography with a colored photosensitive composition in which a pigment is dispersed in various kinds of photosensitive compositions and, since a pigment is used, this method is advantageous in terms of stability with respect to light and heat. Furthermore, since the photolithographic method is used for patterning, the method has high positioning precision, and has hitherto been widely used as a preferable method for producing color filters for large screens and high definition color displays.
When preparing a color filter by means of the pigment dispersion method, a photosensitive composition is applied to a glass substrate using a spin coater or a roll coater and dried to form a coated film and then the coated film is pattern-wise exposed and developed to form colored pixels. These steps are repeated for respective colors to obtain a color filter. As such a pigment dispersion method, a method that uses a negative type photosensitive composition containing an alkali-soluble resin in combination with a photopolymerizable monomer and a photopolymerization initiator has been described (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2-199403).
On the other hand, in recent years, there has been a need to make even higher resolution color filters for solid-state image pickup devices. However, since, in conventional pigment dispersion systems, it is difficult to further improve the resolution, and there is a problem that color unevenness is caused due to coarse particles in the pigment, the conventional pigment dispersion systems are not suitable for applications where a fine pattern is necessary as in solid-state image pickup devices.
In view of these problems, a technique of using dyes in place of conventional pigments has been proposed. However, there is a problem that dye-containing photosensitive compositions are generally inferior in light resistance to pigments. As a method of improving the light resistance, a technique of adding a transition metal complex has been proposed (see, for example, JP-A No. 2004-295116).
On the other hand, various kinds of color filters for solid-state image pickup devices that use organic solvent-soluble phthalocyanine have been proposed as color filters that are excellent in the heat resistance and light resistance (see, for example, JP-A No. 2005-266149).